1. Field of the Invention
The present invention relates to a solid-state imaging apparatus and a camera system.
2. Description of the Related Art
As a focus detecting apparatus for auto focusing (hereinafter, called AF), there is a phase difference detection type which detects a lateral displacement of a luminance signal in two sets of photoelectric conversion element rows. In order to enhance focusing precision and focusing speed of focusing detection, a method of performing accumulation control by processing the maximum value and the minimum value from an output signal of each of the photoelectric conversion elements of photoelectric conversion element rows is used (hereinafter, called Peak Bottom: a PB method). As in the imaging apparatus described in Japanese Patent Application Laid-Open No. 2000-180706, in the PB method, a maximum value processing circuit (hereinafter, called a peak amplifier) and a minimum value processing circuit (hereinafter, called a bottom amplifier) are needed. As described in Japanese Patent Application Laid-Open No. 2000-180706, the peak amplifier and the bottom amplifier include differential input stages and source follower output units. Further, each of the peak amplifier and bottom amplifier includes one clamp capacitor, and performs offset reduction of each of the amplifiers by using each of the clamp capacitors.
As the operation of the imaging apparatus, offset reduction of the aforementioned amplifiers is performed in an offset reduction period for reducing offset. Subsequently, in an accumulation period, accumulation into the photoelectric conversion elements is performed, and control of outputting the maximum value and the minimum value among a plurality of photoelectric conversion elements is performed. After accumulation is finished, optical signals based on the electric charges accumulated in each of the photoelectric conversion elements are sequentially output.